组成图示
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传感器类型
电化学生物传感器
检测对象
葡萄糖（glucose）；样品基质：磷酸盐缓冲液（PBS, pH 7.0）、人血浆/血液样品
检测原理
葡萄糖在 GOD 催化下与溶解氧反应生成葡萄糖内酯和 H2O2。H2O2 扩散至 BCNTs 修饰层，在 +0.60 V 下发生电催化氧化，释放电子并经 GC 电极形成安培电流。BCNTs 因硼掺杂产生缺陷位点，形成边缘位点和富氧基团，降低 H2O2 氧化过电位并提高电子转移速率，使电流随葡萄糖浓度增加。POAP 膜包埋 GOD，维持酶活性并阻挡 AA、UA、AP 等干扰物。该体系无外源标记，依靠酶催化与纳米材料电催化实现信号放大。
检测灵敏度
LOD: 3.6 μM；线性范围: up to 8 mM；R = 0.9940；灵敏度: 2.43 μA mM−1 cm−2 (171.2 nA mM−1)；Kapp_m: 15.19 mM
效应效果
传感器在 5.6 mM 葡萄糖存在下对生理浓度干扰物（0.1 mM AA、0.5 mM UA、0.1 mM AP）干扰较小，电流比分别为 1.05、1.02 和 1.06，表明 POAP 膜具有良好抗污染与选择性。4°C PBS（pH 7.0）保存 20 天后仍保留 80% 响应，前 7 天每天使用仅损失 8%。人血浆/血液样品测定结果与医院 ASCA AG-II 生化分析仪一致，4 例相对误差为 +4.6%、+3.1%、+1.5% 和 −1.0%。作者认为 BCNTs 因增强 H2O2 电催化而适合构建酶型安培生物传感器。
传感器的构成
- 基底/换能器电极：玻璃碳电极（GC）作为工作电极，提供导电基底与安培信号读出
- 纳米材料修饰层：硼掺杂碳纳米管（BCNTs）滴涂于活化 GC 表面，增强 H2O2 电催化氧化
- 固定/屏障膜：聚邻苯二胺（POAP）膜由邻苯二胺（o-AP）与 GOD 电共聚合形成，包埋 GOD 并阻挡干扰物
- 识别元件：葡萄糖氧化酶（GOD）催化葡萄糖氧化生成 H2O2
- 信号标记物：无外源标记；酶催化产物过氧化氢（H2O2）作为电化学信号分子
- 电子供体/底物：葡萄糖（glucose）与溶解氧（O2）参与酶反应，H2O2 在电极氧化提供电子
- 参比/对电极：饱和甘汞电极（SCE）和铂箔（Pt）构成三电极体系
中文摘要
掺杂碳纳米管因独特理化性质在生物分析中备受关注。本文报道了硼掺杂碳纳米管（BCNTs）修饰玻璃碳电极用于安培型葡萄糖生物传感器。由于硼掺杂引入大量缺陷位点，BCNTs 表面形成较多边缘位点和富氧基团，使其对过氧化氢（H2O2）氧化的电催化活性显著高于未掺杂碳纳米管修饰电极。以葡萄糖氧化酶（GOD）为模型酶，通过 GOD 与邻苯二胺（o-AP）电共聚合并包埋于聚邻苯二胺（POAP）膜中固定于 BCNTs/GC 电极。在 +0.60 V、pH 7.0 条件下，传感器表现出高灵敏度（171.2 nA mM−1）、低检出限（3.6 μM）、快速响应（6 s 内）、良好抗干扰能力和稳定性，表观 Michaelis–Menten 常数为 15.19 mM，并评估了其在全血分析中的应用。
英文摘要
Doped carbon nanotubes are now extremely attractive and important nanomaterials in bioanalytical applications due to their unique physicochemical properties. In this paper, the boron-doped carbon nanotubes (BCNTs) were used in amperometric biosensors. It has been found that the electrocatalytic activity of the BCNTs modified glassy carbon (GC) electrode toward the oxidation of hydrogen peroxide is much higher than that of the un-doped CNTs modified electrode due to the large amount of edge sites and oxygen-rich groups located at the defective sites induced by boron doping. Glucose oxidase (GOD) was selected as the model enzyme and immobilized on the BCNTs modified glassy carbon electrode by entrapping GOD into poly(o-aminophenol) film. The performance of the sensor was investigated by electrochemical methods. At an optimum potential of +0.60 V and pH 7.0, the biosensor exhibits good characteristics, such as high sensitivity (171.2 nA mM(-1)), low detection limit (3.6 microM), short response time (within 6s), satisfactory anti-interference ability and good stability. The apparent Michaelis-Menten constant (K(m)(app)) is 15.19 mM. The applicability to the whole blood analysis of the enzyme electrode was also evaluated.